The present invention relates to a method and apparatus for forming a resist pattern on a substrate used in semiconductor fabrication processes and a resist pattern used for a photomask such as a reticle.
Recently, chemically amplified resist patterns are formed by means of the lithographic technique utilizing the KrF excimer laser exposure. Especially, negative resist, which provides unexposed portions that dissolve in developing solution, is important for super-resolution techniques (Levenson phase shift masks).
However, if chemically amplified negative resist is used to produce a line-and-space pattern 21, for instance, microbridges 22 that partially connect adjacent portions of the pattern are readily formed, as shown in FIG. 1, reducing yields.
An object of the present invention is to provide a method and apparatus for forming a resist pattern on a substrate, which suppresses generation of microbridges.
According to an aspect of the present invention, a method of forming a resist pattern on a substrate, comprises the steps of: forming a resist film on the substrate; supplying a developing solution onto the resist film; and submerging the substrate and the resist film formed thereon in a rinsing liquid kept in a rinsing tank; and applying ultrasonic vibration to the rinsing liquid to rinse the developing solution from the resist film submerged in the rinsing liquid.
According to another aspect of the present invention, an apparatus for forming a resist pattern on a substrate comprises: a rinsing tank which keeps rinsing liquid for rinsing developing solution remaining on a resist film formed on the substrate; and an ultrasonic vibration mechanism which applies ultrasonic vibration to the rinsing liquid kept in the rinsing tank.